Centerless bar grinder



Sept. 18, 1962 Filed NOV. 18, 1960 E. W. MOUER CENTERLESS BAR GRINDER Hil I M NH HIIIIH 3 Sheets-Sheet 1 SOL-l 4a soL-z INVENTOR EA RL W. MOUER ATTORN EY Sept. 18, 1962 E. w. MOUER 3,054,228

CENTERLESS BAR GRINDER Filed Nov. 18, 1960 3 Sheets-Sheet 2 INVENTOR EARL w. MOUEA BY ATTORNE p 1962 E. w. MOUER 3,054,228

CENTERLESS BAR GRINDER Filed Nov. 18, 1960 3 Sheets-Sheet 3 L5 Ll L2 MACHINE START MACH/NE STOP F FORWARD T CLUTCH INVENTOR EARL W MOUER TTORNEY Patented Sept. 18, 1962 Free 3,054,228 CENTERLESS BAR GRINDER Earl W. Mouer, Waynesboro, Pa., assignor to Landis Tool Company, Waynesboro, Pa. Filed Nov. 18, 1960, Ser. No. 70,196 7 Claims. (Cl. 51-103) This invention relates to centerless grinders, particularly machines arranged for grinding long workpieces such as bars and tubes.

Long workpieces, such as bars and tubes, must pass through a centerless grinder several times in order to mind them to the desired size and finish. In the past, attachments have been provided to return the work to starting position. More recently, this has been accomplished by reversing the direction of rotation of the regulating Wheel at the end of one pass of the workpiece to feed the Workpiece in the opposite direction and to perform a grinding operation on a workpiece during this return pass.

It is, therefore, an object of the present invention to provide automatic means for reversing the direction of rotation of the regulating wheel as the workpiece completes a pass between the grinding and regulating wheels in each direction.

Another object is to provide for advancing the grinding and regulating wheels after each pass of the workpiece be tween said wheels or after a series of passes.

Another object is to rotate the regulating Wheel at either of two speeds, a low speed for grinding and a high speed for dressing, or for returning a workpiece rapidly to starting position.

Another object is to provide means whereby said high speed rotation of the regulating wheel may be provided in either direction of rotation.

FIG. 1 is a plan View of a centerless grinder arranged for grinding long workpieces.

FIG. 2 is an end elevation showing the means for rotatably supporting a workpiece beyond the bed of the machine.

FIG. 3 is an electric circuit.

Bed has a grinding wheel support 11 slidably mounted thereon. Control wheel support 12 is also slidably mounted on bed 10 in line with grinding wheel support 11. Grinding wheel 15 is rotatably mounted on spindle 16 in griding wheel support 11. Grinding wheel 15 is rotated by motor 17. Grinding wheel 15 may be adjusted toward and from control wheel support 12 by means of feed screw 18 rotatable in nut 19.

Feed screw 18 may be rotated by hand Wheel 20 operable through suitable gearing to rotate shaft 21 having a worm 22 in operative relation with worm gear 23 and feed screw 18. Shaft 21 may also be rotated by ratchet 25 actuated by pawl 26. Pawl 26 may be actuated by any suitable mechanical, electrical or hydraulic device. For the purpose of illustration, the pawl actuating mechanism disclosed here is a solenoid 1.

Control wheel 30 is rotatably supported on spindle 31 on control wheel support 12. The means for rotating control wheel 30 consists of a reversible motor 32 operable through a two-speed drive consisting of a low speed pulley 33, a high speed pulley 34 and a speed change clutch 35 operable by knob 36.

The means for adjusting control wheel 30 toward and from grinding wheel 15 is similar to the grinding wheel feed means and includes a ratchet 39, a ratchet actuating solenoid 2 for operating a pawl (not shown), and hand wheel 40.

Workpiece W is supported in operative relation to grinding wheel 15 and control wheel 34} on a conventional centerless thru feed work rest 50. Extended supporting means for long bars and tubes is disclosed in FIG. 2

and a similar device is shown in greater detail in US. Patent 2,775,077, granted December 25, 1956. Briefly, it consists of spaced angularly positioned rollers 60 adjustalbly supported on support members 6 1. A vertical standard 62 is positioned near the outer end of each support member 61.

At each end of support members 61 is mounted a limit switch, 1LS at the left hand end and 2LS at the right hand end. Each limit switch is positioned so that when it is engaged by one end of workpiece W, a substantial portion of the other end of workpiece W is still between grinding wheel 15 and control wheel 30.

Operation Closing machine start switch 70 completes a circuit through normally closed machine stop switch 71 to energize machine relay CRM.

Contacts 1 and 2 of machine relay CRM close, to provide current for the various elements of the circuit.

Contact 1 of machine relay CRM also provides a holding circuit through machine stop switch 71.

To start motor 32, forward push button 75 is closed to complete a circuit through normally closed relay contact 2CR1 to energize relay lCR.

Relay contact 1CR1 closes to provide a holding circuit for relay lCR through relay contact 2CR1.

Normally closed relay contact 1CR2 opens in the cir cuit to relay 2CR.

Relay contact 1CR3 completes a circuit through timer contact relay 1TR1 and normally closed relay contact 1MR5 to energize control wheel motor forward relay 1MP and timer relay TR.

Relay contact 1MF1 also completes a circuit to energize count clutch in the circuit to control wheel feed solenoid 2 to energize feed solenoid 2 to advance control wheel 30 after one or more passes of workpiece W through the machine.

Relay contact 1MF1 completes a circuit to grinding wheel feed solenoid 1 to actuate ratchet 25 to advance grinding wheel 15 by a predetermined increment.

Contacts 2, 3 and 4 of relay IMF complete a circuit to energize motor 32 for forward or conventional rotation.

When workpiece W completes the first pass through the machine, it actuates limit switch 1LS, opening limit switch contact 1LS1 and closing limit switch contact 1LS2.

Opening limit switch contact 1LS1 opens the holding circuit through relay contact 1CR1 and normally closed relay contact 2CR1 to deenergize relay 1CR.

Limit switch contact 1LS2 completes a circuit through normally closed relay contact 1CR2 to energize relay 2CR.

Normally closed relay contact 2CR1 opens in the previously opened circuit to relay lCR.

Relay contact 2CR2 provides a holding circuit through normally closed relay contact 1CR2.

Relay contact 1CR3 opens the circuit through timer relay contact 1TR1 and normally closed contact 1MR5 to deenergize relay IMF and timer relay TR.

After a predetermined interval, timer relay TR closes to complete a circuit through normally closed relay contact 1MF5 to energize relay IMR and timer relay lTR.

Normally closed timer relay contact 1TR1 and normally closed relay contact 1MR5 open in the circuits to relay IMF and timer relay TR.

Relay contact 1MR1 completes a circuit to count clutch 80.

Relay contact 1MR1 also completes a circuit to grinding wheel feed solenoid 1 to advance grinding wheel 15 for the next pass of workpiece W.

Contacts 2, 3 and 4 of relay lMR complete a circuit to motor 32 to start rotation in the opposite direction.

Workpiece W rotates and moves axially in the opposite direction and the grinding operation continues.

Reversing of the control wheel 30 may be done manually by forward push button 75 and reverse push button 76.

At the beginning of this movement, limit switch ILS is released, closing limit switch contact 1LS1 and open ing limit switch contact 1LS2.

At the end of the reverse movement, limit switch contact 2LS1 is closed and limit switch contact 2LS2 is opened.

Limit switch contact 2LS2 opens a circuit through normally opened control relay contact 2CR2 and normally closed control relay contact ICRZ to deenergize relay 2CR.

Control relay contact 2CR3 opens to deenergize relay lMR to stop the reverse rotation of control wheel 30 and to deenergize timer relay 1TR.

Limit switch contact 2LS1 completes a circuit through normally closed control relay contact 2CR1 to energize relay ICR.

Control relay contact 1CR3 completes a circuit through timer relay contact 1TR1 and normally closed relay contact 1MR5 to energize timer relay TR and relay IMF.

Normally closed timer relay contact TRl and normally closed relay contact IMFS open to deenergize timer relay 1TR and relay lMR.

After a predetermined interval, timer relay contact 1TR1 closes to complete a circuit through normally closed relay contact 1MR5 to energize relay IMF and timer relay TR.

Relay contact 1MF1 completes a circuit through grinding wheel feed solenoid 1 and through count clutch 80 to the control wheel feed solenoid 2.

Contacts 2, 3 and 4 of relay MF complete a circuit to start forward rotation of motor 32 to rotate and advance workpiece W in the forward direction.

I claim:

1. In a centerless grinding machine, peripherally opposed grinding and control wheels, a work support between said wheels, a feed mechanism for changing the space between said wheels, means for actuating said feed mechanism, means for etfecting a reciprocable traversing movement of a workpiece between said wheels including means to reverse direction of rotation of said control wheel, and a switch in the path of the workpiece for actuating said feed mechanism and said control wheel reversing means.

2. In a centerless grinding machine, peripherally opposed grinding and control wheels, a work support between said wheels, means for rotatably supporting longitudinal workpieces such as bars and tubes including longitudinally spaced, angularly adjustable rollers, supporting means for said rollers, means for effecting a reciprocable traversing movement of a workpiece between said wheels including control means in the path of said workpiece for reversing the direction of rotation of said control wheel.

3. In a centerless grinding machine, peripherally opposed grinding and control wheels, a work support between said wheels, a reversible adjustable speed motor for driving said control wheel, means for effecting a reciprocable traversing movement of a workpiece between said wheels comprising control means at each end of said work support and arranged to be actuated by a workpiece for reversing said control wheel motor.

4. In a centerless grinding machine, peripherally opposed grinding and control wheels, a work support between said wheels, a reversible adjustable speed motor for driving said control wheel, means for effecting a reciprocable traversing movement of a workpiece between said wheels comprising oppositely positioned reversing switches in the path of the workpiece for reversing said control wheel motor.

5. In a centerless grinding machine, peripherally opposed grinding and control wheels, :1 work support between said wheels, a reversible motor for driving said control wheel, means for reversing said motor, a speed changing device between said motor and said control wheel, said speed changing device being operable to change the speed of said control wheel in either direction of rotation.

6. In a centerless grinding machine, peripherally opposed grinding and control wheels, a work support between said wheels, a reversible adjustable speed motor for driving said control wheel, said control wheel being mounted for angular adjustment for effecting endwise movement of a workpiece between said wheels, extended supporting means on each side of said grinding machine for accommodating workpieces longer than the width of the machine, said supporting means including spaced, adjustably mounted rollers angularly positioned to assist in the endwise movement of the workpiece, and control means for each end of said extended supporting means arranged to be actuated by the endwise moving workpiece for reversing said control wheel motor.

7. In a centerless grinding machine, peripherally opposed grinding and control wheels, at work support between said wheels, adjusting means for changing the space between said wheels, a reversible motor for driving said control wheel, means for rotatably supporting longitudinal workpieces such as bars and tubes including longitudinal spaced, angularly adjustable rollers, supporting means for said rollers, means for efiecting a reciprocable traversing movement of a workpiece between said wheels including switches mounted on said roller supporting means in the path of said workpiece for reversing the direction of rotation of said control wheel and for actuating said adjusting means.

References Cited in the file of this patent UNITED STATES PATENTS 2,211,685 Binns et al. Aug. 13, 1940 2,735,237 Balsiger Feb. 21, 1956 2,807,917 Fuller et al. Oct. 1, 1957 2,872,757 Ekholm Feb. 10, 1959 2,913,854 Ekholm Nov. 24, 1959 2,933,860 Snyder Apr. 26, 1960 

